Molded diaphragm structure



F M 1 I May 12, 1953 D. e. GRISWOLD MOLDED DIAPHRAGM STRUCTURE Original Filed Sept. 9, 1943 2 Sheets-Sheet l .3 14ml 5 Gwwa May 12, 1953 D. G. GRISWOLD MOLDED DIAPHRAGM STRUCTURE Original Filed Sept. 9, 1943 2 Sheets-Sheet 2 3 W cm Yo I,

flalmZd nfrwaZd !\(!II.I!. U 7 v (a 6 A J H D 0 a /M Patented May 12, 1953 2,638,127 MOLDED DIAPHRAGM STRUCTURE Donald G. Griswold, Alhambra, Calif., assignor to Clayton Manufacturing Company, Alhambra, Calif., a corporation of California Original application September 9, 1943, Serial No. 501,701. Divided and this application January 16, 1946, Serial No. 641,421

7 Claims. (Cl. 137- 793) The present invention relates to a novel molded diaphragm structure adapted for general use in valves, siphon breakers, etc.

One of the novel features of the present diaphragm is that it includes a, button integrally formed therewith of such shape and configuration as to cooperate with an annular seat to.

effect quiet sealing and thus eliminate the usual noise and chattering commonly encountered with conventional diaphragm structures.

Another feature of the diaphragm is that the body and button may be reinforced with fabric, if desired, and made of rubber or neoprene having a predetermined, desired Shore scleroscope hardness. In certain instances, the main body portion of the diaphragm may be made of "neoprene or rubber of one hardness and the button of another hardness.

For the purpose of illustrating the adaptability of the present diaphragm for various uses, the same is disclosed herein in connectionwith an automatic check valve and with an automatic vacuum or siphon breaker. One of the principal advantages of the present diaphragm in valve structures is that it eliminates the usual valve stem, clamping plates, valve stem guides, etc., and, being devoid of the usual valve stem opening, it eliminates the difliculties encountered in conventional valves when used with, for example, high air pressures, because it prevents the air from infiltrating into and through the body of the diaphragm and causing leakage.

The principal object of the invention is to pro-- vide a molded diaphragm structure adapted for general use in valves, etc., wherein the diaphragm includes a portion which directly engages a seat and cooperates with said, seat and the opening therein to produce quiet operatiom Other objects and advantages of the invention will be apparent from the following description, taken in conjunction with the accompanying drawings, in which: i

Fig. 1 is an enlarged elevational view .of a diaphragm constructed in accordance with the principles of the invention;

Fig. 2 is a longitudinal sectional view through i I phragm such as shown in Fig. 1;

Figs. 3, 4 and 5 are diagrammatic views illustrating the novel coaction between the dia phragm button and an annular seat during the downward flexing of the diaphragm, and whereby chattering, squealing and other noises incident to' closing are eliminated; Fig. 6 is an elevational view of an automatic an automatic check valve containing a dia- 2 siphon breaker including a diaphragm embodying the principles of the present invention;

Fig. 7 is a transverse sectional view taken on the line 1-1 of Fig. 6;

' Fig. 8 is a diagrammatic view illustrating the manner in which the siphon breaker shown in Figs. 6 and 7 may be installed in a pipe system of a house or other building to prevent backsiphoning; and.

Fig. 9 is a view similar to Fig. 8 but showing amodified piping installation.

Referring now to Fig. 1, the diaphragm is generally indicated by the letter D and includes a circular body portion I provided with a relatively thick, integral, central button 2 consisting of a circular boss 3 and a circular protuberance or mound 4 formed upon said boss. The thickness of the-body portion'l is indicated by the letter K and the thickness of the boss 3 is indicated by the dimension 3K inasmuch as said boss'is approximately three times as thick as the body portion I. The periphery of the boss 3 is merged with the body portion I along an arc defined by a radius R which is equal to 3K, the axial thickness of said boss. The protuberance or mound 4 is indicated as having athickness 2K; that is, about twice as thick asthe body portion l. Half the height of the mound 4, indicated by the dimension K, constitutes a cylindrical portion 5,whereas the remainder of the periphery of the mound 4 is curved upon an are C having a radiusR' equal to the dimension K. The lower side of the mound 4 is flat asindicated'at B. i

Thediaphragm Dmay be made of rubberbut is preferably made of neoprene having a Shore scleroscope hardness ofto 80. Neoprene is preferred to rubber becauseit will not stick to a; brass seat, whereas, rubber as it ages, has a tendency to do so. Thebody I, and the button :2 may be reinforced with laminated fabric (not shown) if desired, in" order to add strength thereto. For certain small valves, the body portion I and the button 2 will both be made of a hardness of 60, as" measured by the Shore scleroscope. For larger types of valves, the body I will havea hardness of about 60 and the button 2 will have a hardness or about 80.- Of

course, the body I may be made of a hardness ranging from 60 to 80, as may alsothe button '2. The foregoing range of Shore scleroscope hardness of 60 to provides a diaphragm structure of the desired flexibility conducive to the mode of coaction with a cooperating seat dea scribed hereinafter.

Fig. 2 shows the manner in which the diaphragm D may be incorporated in an automatic check valve. The check valve is generally indicated by the numeral 9 and includes a body ll] having an inlet opening .I l and an outlet opening l2 sepauated @by a partition wal1 including :a vertical portion [3 and an inclined wall portion 14 which are merged to provide a circular opening l5 between the chambers ll and 12. The opening I5 is surrounded by an upwardly protecting flange I6, the upper annular .suriace ;ll of Which forms a seat cooperable with the hutton z of the diaphragm D. The surface ll maybe rrnade fiat, but better results are obtained if the same is slightly inclined downwardly and outwardly on an angle of about 5 to the horizontal, as shown in Fig. 3.

The diaphragm D is disposed between the valve body It and a cover plate 13 secured to the body bye-suitable number of machine screws .1 9, The cover 11.8 is {dished to provide a pressure chamber :28 above he aphragm l... Communication b tween the outlet opening 12 and the diaphpagm, pressure chamber 219 is established by a passageway ,21 in the valve body Ill, which .communir hates with a passageway 22. in the cover l8 openine into he pressure chamber 213. It will be p parent that, as the pressure builds upon the out.- let side 12 of the valve asu h pr ssure will be communicated through the passageways "21 and 252,120 the pressure chamber 29 and cause downwardnexing of the diaphragm D to cut off flow between the chambers H and 12. In this man- :ner. he'check valve :S'automatieauy closes in resp nse to chan es in pressur in th .outlet cham er, 2. it will als be apparentthatas the pressure sleeps in the outlet chamber 12, the dia. phragm ?D "will be raised from its seat I1 by the pressure in the inl t c amber H, and rai insbf th diaphragm will cause-the fluid in the pres sure ch mb r at to be iorced out or said cbam her through the passageways 22 and 2 1 back into the eutlet chamber 12, to eyentuallfy permit rail openin of the valve.

The "mound I4 has a diameter-indicated by the letter B, which for a 1% valve is about 0.02 to 0.03 of an inch less than the diameter of'the seat opening 15. The diameter of the lower face 215 of the'boss 3 is indicated by the dimension A and preferably is slightly larger than the outside diameter of the seat H.

The novel manner in which the diaphragm D cooperates with the seat I? durin -closing of the valve is diagrammatically illustrated in Figs. 3

to =5,'the clearances being exaggerated to vfacili {tat'e illustration. Fig. '3 shows the body "I of the diaphragm 'D substantially fiat and when in'this condition the lower face 25 of the boss 3 lies in will firsttengage said edge at a point 2'! (Fig. 5)

at .one .side of the seat and gradually and progressively engage the remainder of said edge on both sides oi said point until final and complete contact is made at a point substantially diametrically opposite the initial point of engagement.

..Fig. ;5 shows the seat [1 contacted by the boss 3 for about *half-wayaround its periphery. Thus,

.theppotuberance or mound 4 enters the seat a horizontal plane parallel with that of the plane cithe body 't'with the mound 4 disposedeibove the seat it. As the diaphragm D is flexed downwardly due to the increasing pressure the chamber 2:13, the central portion .of "said diaphrasm is flexed downwardly out of a horizontal pla e and is caused t assume the somewhat dis ed ontour indicated at 26 in Fig. 4, The mound 4 enters the openin 15 and the lower disc 25 of the b ss 3 is aused to assume a sli ht angle to the horizontal, the portions defined by the arcs C being flexed slightly outwardly into closer proximity with the inner surface of the pening 15. The curvature of the arcs C gradually eon tricts the flow between the inlet and outlet chambers l I and I2 of the valve as the mound 4 further enters the opening [5. At theopening l5 axially to gradually constrict the flow through the seat openin and, while this is being done, the Isuriace 215 is approaching the seat I] and upon engagement therewith gradually cuts off flow circumferentially through the opening 115. It is such gradual constriction and cutting offof flowthrough the opening 15 (due to the gradual axial and circumferential restriction of ifiow through said opening [5), which results in the unusual .quiet operation of the diaphragm. Moreover, it is the predetermined flexibility of the diaphragm D within the scleroscope hardness rang .of 60 to .80 and the specific shape of the button 2 which permit such .coaction,

Referring now to Figs. .6 and 7, a modified dim aphragm D, similar to the diaphragm 2D, except that it is provided with a central passageway .3 I, is incorporated in a siphon breaker generally indicated by the numeral39. The siphon breaker ,30 includes ,a hollow cylindrical mountin element .32, and a body comprising a hood 33 and'a cover plate se. .The diaphragm D is clamped between the cover 34 and a horizontal flange 915cm thehood 33 said hood and cover being secured together by a suitable number of screws 3.6.. The mounting member 32 includes a cylindrical portion 3'! proiectingupwardly intothe hood 33 and terminating at its upper end in an inclined face 38 adapted to serve as an annular seat for a boss 3' on the diaphragm D. The mounting member 32 includes an intermediate hexagonalgfiange 45 a ainst which a lower reduced end 4| of thehood is adapted to engage. The inner surface of the portion 41 snug- 13; engages the outerperiphery of the cylindrical portion 31 and the hood 33 is preferably mounted on the mounting member' 32 by sweating, the portion 4} onto the portion 31, although it wlllbe understood that other means of securing the hood to the portion 37 can be employed. The hood 33 has an enlarged-portion 42 adjacent the reduced'end 4| provided with a series of vent openings 4.3, the total area of which is at least as great as the area of the opening surrounded by the annular seat 38. The cover 34 is dished as indicated at 44 to provide apressure chamber above the diaphragmD'.

Fig. 8 diagrammatically illustrates the manner in which the vacuum breaker 31] shown in Figs. Sand 7 maybe. installed in a piping systemassociated with a dwellin or other building. It will be understood that the vacuum breaker .39 may be mounted at each plumbing fixture, but for the sake of economy only one need beused and can be conveniently mounted at the highest pointin the line supplying water to the dwelling or building. Thus,in Fig. 8 the vacuum breaker 30 is mounted at the highest point between two vertical pipe lines 45 and 46. The line 45 is connected with a supply pipe 41 and the line 46 is connected by branch lines 48 and 49 with various plumbing fixtures in the building such as wash basins 50, toilet 5|, and a stationary tub 52. A shut ofi valve 53 isconnected in the service line 41.

In operation, so long as there is any pressure in the line 45, fluid will flow through the passageway 3l in the diaphragm D into the chamber 44, and as the pressure in said chamber builds up, the diaphragm D will be flexed downwardly to engage the seat 38 (in the same manner described in connection with the valve of Fig. 2) to automatically seal off the upper end of the mounting member 32 from the atmosphere. The siphon breaker 30 will remain closed so long as the pressure in the line 45 is above atmospheric pressure. However, if the pressure in the line 45 drops below atmospheric pressure for any reason, the fluid from the chamber 44 will flow back through the passageway 3| in the diaphragm D into the pipe line45, and atmospheric pressure effective through the vent openings 43 will act upon the lower side of the diaphragm D and flex it upwardly out of contact with the seat 38 and thus vent the pipe 45 to the atmosphere and prevent the formation of any vacuum therein which would tend to cause back-siphoning of liquid from the basin 50, toilet 5| and tub 52. In this manner, all possible contamination of the water in the line 45, supply pipe 41 and any main connected with said supply pipe is avoided, as is also any damage that might result by water rushing back into the line 45 if the vacuum were not broken.

Fig. 9-illustrates' a modified piping system including the siphon breaker 3B in which said siphon breaker is not connected in thesystem at the highest point thereof. Thus, the siphon breaker 30 is shown connected directly in a supply line 54. A check valve 55, which may be of conventional construction, is connected on the building side of the siphon breaker 30 and a conventional globe or gate shut off valve 55 is connected in the line 54 on the inlet side of the check valve 55. Water from the supply pipe 54 is supplied to the various fixtures in the building through a riser 51. In this system, if the pressure should fail in'the supply pipe 54, thesiphon breaker 30 will automatically open and connect the supply line 54 with the atmosphere in the same manner described in connection with Fig. 8.

Moreover, the check valve 55 will prevent the 1 water in the riser 51 and other piping in the dwelling from flowing back into supply line 54. The check-valve 55 alone would prevent objectionable back-siphoning, but would not relieve any vacuum condition that might be created in the service line 54. On the other hand, the siphon breaker 3|] avoids all possibility of producing a vacuum in the supply line 54 and the dangers incident thereto.

This application is a division of my copending application Serial No. 501,701, filed September 9, 1943, and which has now matured into Patent 2,394,911.

It willbe understood that the diaphragm disclosed herein is not limited to use in valves and siphon breakers but is adapted for general utility. It will also be apparent that various changes may be made in certain details of construction of the valve and siphon breaker per se, without departing from the spirit of the invention or the scope of the annexed claims. V 1

I claim: l. A neoprene diaphragm adapted to be received within the opening in said annular seat to constrict flow therethrough before said annular surface portion engages saidseat, said body portion having a Shore scleroscope hardness of about 60 and said boss and protuberance having a Shore scleroscope hardness of about 80. 1

2. A diaphragm comprising: a substantially circular flexible body; a substantially circular relatively rigid central boss formed integral with said body and having the peripheral wall thereof merged into said body upon an arc, said boss including an annular marginal surfaceada'ptedto engage an annular seat, and a protuberance onengage the remainder of the seat on both sidesof said point until complete contact all the way around the seat is-made. v 3. A diaphragm comprising: a substantially circular flexible body; a substantially circularrelatively rigid central boss formed integral with said body, said boss having a thickness approxi-* mately three times as great as the thickness of said circular body, the peripheral wall of s'aid zbo'ss merging with said body upon an are having; a;

radius substantially equal to the thickness of said boss, said b'oss including an annular surface'on the lower side thereof adapted to engage an annular seat and a protuberance on said boss within the peripheral limits of said annular seat engaging portion, said protuberance including a cylindrical portion having a thickness of approxi'-. mately twice that'of-the thickness of said body. said cylindrical portion terminating in a flat lower end face, the lower corner of-said'cylindri-f cal portion being rounded upon, an arc having a radius substantially equal to that of the thickness of said body, said annular seat engaging portion being adapted, under flexing movement of said diaphragm, to first engage the seat at one point and then to gradually and progressively engage the remainder of the seat on both sides of said point until complete contact all the way around the seat is made.

4. A diaphragm comprising: a substantially circular flexible body; a substantially circular relatively rigid central boss formed integral with said body, said boss having a thickness approximately three times as great as the thickness of said circular body, the peripheral wall of said boss merging with said body upon an arc having a radius substantially equal to the thickness of said boss, said boss including an annular surface on the lower side thereof adapted to engage an annular seat and a protuberance on said boss within the peripheral limits of said annular seatengaging portion, said protuberance including a cylindrical portion having a thickness of approxicomprising: a flat? disc-like body portion; an integral boss on saidbody portion, said boss being substantiallyless: flexible than said body portion and including a portion adapted to engage an annularseat':and' a central integral protuberance on said boss" mately twice that of the thickness of "said body. said cylindrical portion terminating in a flat lower end face, the lower corner of said cylindrical portion being rounded upon an are having a radius substantially equal to that of the thickness of said body, said -tdiaphragin being made of neoprene and having a Shore scleroscope hardness of 69 to 80, :said annular seat engaging portion being adapted, under flexing movement of said diaphragm to first engage the seat at one point and then :to gradually and progressively engage the remainder of the seat on both sides of said point until complete contact all the way around the seat ismade.

*5. A diaphragm comprising: a substantially circular flexible body; a substantially circular relativelyrigid central boss formed integral with said body and having the peripheral wall thereof merged'into said body upon an arc, said boss including; an annularmarginal surface adapted to engage an annular seat and a protuberance on said boss Within the peripheral limits of said annular seat-engaging portion, said protuberance including a cylindrical portion and a lower end iace,;said cylindrical portionbeing merged at its'gperiphery with said endface by a 'rounded cornerysaid annular seat engaging port-ion being adapted, under flexing movement of said diaphragm,to first engage the seat at one point and then -.to ,gradualb' and progressively engage the remainder ofvthesseat on both sides of said point until complete contact all the way around the seatis'made.

-6, A diaphragm comprising: a substantially circular flexible body; a substantially circular relativelyrigid central boss formed integral with said body,said boss having a thickness approxi mately three times astgreat as the'thickness of said-"circular body, the neripheral wall of said boss merging with said bodyupon an are having a .radiussubstantially equal to the thickness-of said boss, said boss including an annular surface on the. lower-aside thereof adapted to engage an annular seatand a protuberance on said boss within theiperipheral limits of said annular seatengaging portion, said protuberance includingpa cylindrical portionhaving a thickness of approximatelytwi'ce that of the thickness ofsaid body, said cylindrical portion terminating in a lower end-face, the lower corner of said cylindrical portion being rounded upon an arc merging into said lower endrtaceand having airadius substantially equal toathat of the thicknesslof said body. said 8 annular seat engaging portion being adapted, under flexing movement of diaphragm. to first engage the seat at one point and'then-to gradually and progressively engage the remainder of-the seat on both sides of said pointuntil complete contact all the way around the seat is made.

7. A diaphragm comprising: a substantially circular flexible body; a substantially circular relatively rigid central boss formed integral with said body, said boss'having a thickness approximately three times as great as the thickness of said circular body, the peripheral wall of said boss merging with said body upon an are having a. radius substantiallyequal to the thickness of said boss, said boss including anannular surface on the lower side thereof adapted to engage an annular seat anda protuberance on .saidboss within the peripheral limitsof said annularseatengaging portion, said protnberanceincludinga cylindrical portion having a thickness of approximately twice that of the thickness of said body. saidcylindrical vportion terminating in a lower end face, the, lower corner of said 'cylindricalpon tion being rounded upon an arc merging into said lower end face and having a radius substantially equal to that of the thickness of said body, said diaphragm bein made of neopreneandhaving a Shore scleroscope hardness of to 80, said annular seat engaging portion being adapted, under flexing movement of said diaphragm, to first engage the seat atone point and then to gradually and progressivelyengage the remainder of, the seat on both sides of said point untilucomplete contact all the way around the seatis made.

DONALD .G. GRISWOLD.

References Cited inthe file of this patent WITED'STA'IES PATENTS Sweden June20,.1935 

